That Alan Moore and Dave Gibbons's epochal 1986 comic book miniseries Watchmen would not survive a translation to cinema intact was an inevitability: it is far too long for even the most indulgent running time, and too much of its impact come from formal elements unique to the comic medium.

Taking that as read, the question about Zack Snyder's new movie adaptation of the book is neither "Does this film triumph because of its fidelity to the source material?" nor "Does this film fail because of its departures from the source material?", though these seem to be the primary criteria for the fanboy armies that brought Watchmen to an impressive but still somehow underwhelming $55 million opening weekend. To my mind, the better questions are, "Does this film, in its film-ness, approximate the feeling and meaning of the book?" and the even simpler, "If the book didn't exist, would this be a good film?" My answer for both of these questions is "No, not really", although I'll freely admit that on both counts it's far, far better than I would ever have expected from the "visionary" director of the godawful 300 (and the shockingly decent remake of Dawn of the Dead, but that feels like a different lifetime by now).

Watchmen, for the benefit of those happy few who have been disconnected from all media for the last few months, is a story about the death of superheroes, which in Moore's original conception was not something worth lamenting.* Specifically, it is about the Minutemen (renamed the Watchmen for the movie, since people no longer understand metaphorical titles), a group of costumed heroes dating back to the 1940s that had a mostly fresh cast in the 1970s, when legislation was passed making costumed heroics illegal. The story begins in 1986, when Eddie Blake, A.K.A. The Comedian, a superhero in the government's employ, is brutally killed, and the rest of the old Minutemen realise that someone is hunting them down.

This was all bracing, original stuff when Moore and Gibbons first hatched it, although films like The Incredibles and comic book events like the Marvel Universe Civil War have taken away a bit of its thunder now. What still sets Watchmen-the-book apart from its followers is that Moore made no attempt to hide his lack of respect for the heroic figures he presented. The 1986 edition of the Minutemen includes virtually nothing but failed fuck-ups: in life, The Comedian was a brutal bully, while the surviving members include Dan "Nite Owl" Dreiberg, an overweight, milquetoast trust fund kid who fights crime in a costume out of something like a sexual kink; Rorschach, a right-wing sociopath whose idea of justice is frighteningly vengeful; Laurie "Silk Specter" Jupiter, a non-entity who only took up the job because her mom made her; Adrian "Ozymandias" Veidt, a smart rich prick with a touch of insanity to him; and Jon Osterman, a physicist who was destroyed in an accident in the '50s and turned into Dr. Manhattan, a walking nuclear reaction able to reassemble molecules at will and see all moments in time at once, but divorced from nearly every human emotion as a result.

When Snyder was announced as director, I had one concern that outweighed everything else: that his take on the material was going to focus on its awesomeness, and as a result, these pathetic and/or horrible figures were going to be reshaped according to an adolescent's idea of what Watchmen entailed. In the book, the characters are all unambiguous anti-heroes, except for those whom are frightfully ineffectual; the movie does not appear to know what the word "antihero" means.

And this is where we get to the point where I gave up on hoping for "Watchmen-the-book The Movie", and accepted that I'd be watching Zack Snyder's Watchmen on its own terms if I wanted to get anything out of it all, however much shallower than the original material that would be. And in patches, this approach works. I know that some people regard 300 as a great action movie, and I'm super-happy for them, but for me it was basically a train wreck. So it's a good surprise to see that Snyder can, in fact stage an action setpiece when he has to, and the opening scene in Watchmen, a fight between The Comedian and a shadowy assailant, is pretty tremendously well-done. This is followed, almost immediately, by what very nearly could be my favorite single passage of the film, the opening credits sequence, which traces the history of the Minutemen since WWII, in 3-D tableaux. It's not actually a new trick for credit sequences, but it's still fresher than anything to follow; the only gaping flaw is the use of Bob Dylan's "The Times They Are A-Changin'", but let us return to that.

After the opening, the film quickly rushes into 300 and Sin City territory: adapt a comic book by recreating it with panel-by-panel accuracy. Look, I loved Sin City, but the appeal of this idea is long since rotted away, and the film Watchmen frequently chokes on its own fidelity, a mummified version of the original story. This includes its use of the book's story structure; something of a fool's gambit, given that the book was originally twelve issues, and still reads as twelve very formally separate chapters. This has the most profound negative impact on the movie during Dr. Manhattan's flashback to his creation: this is one of the highlights of the book, jumping decades in between panels over the course of 24 pages, but in the more fluid environment of the cinema, this sequence grinds the story to a dead halt, and is probably the chief reason that the film feels like every one of its 163 minutes.

Such slavish devotion to the comic leaves only a little room for any director to express much personality, but Snyder grabs each chance he gets, and occasionally the results are much better than I would ever have assumed possible. In particular, his well-documented love of speed ramping (movement slows down and speeds up and goes back to normal all in one shot) isn't altogether dreadful here, like it was in 300; I can think of three or four places where it actually worked to give a moment more "oomph" rather than, to paraphrase the director, "giving us more time to watch as one dude kicks another dude in the face". Which sentiment reveals just about all that one needs to know about Snyder's approach to violence in the cinema (and indeed, parts of the movie are a bit violence porny, and that is a problem to me thought not a surprise, your mileage may vary).

There are still a lot of amateur-hour mistakes in the direction, though: if three or four of the speed ramps work, that leaves 20 or 25 that don't work. His love of violence I just mentioned; and then there is the jaw-dropping use of music, easily the worst single aspect of the film. The Dylan song is merely mis-used and a bit overreaching, but then he goes and uses Simon & Garfunkel's "The Sound of Silence" in a funeral scene, forgetting that that song is inextricably linked to another movie; he plucks some of Philip Glass's Koyaanisqatsi score for Dr. Manhattan's sojourn on Mars, apparently thinking that one esoteric thought piece is the same as another; and in the worst moment of the film by far - and possibly the worst movie moment so far in all of 2009 - he sets a crudely-staged sex scene to Leonard Cohen's "Hallelujah", observing neither that this is an altogether overused song, nor that the moment which results is soul-despairing. This is a sex scene that makes even the notorious climax (if you will) of Spielberg's Munich look sober-minded and well-executed.

About the cast I have said little because there is little to say. The one genuinely good performance, I think, is given by Jackie Earle Haley as Rorshach; Patrick Wilson as Dan Dreiberg and Jeffrey Dean Morgan as Eddie Blake are fine, and probably no better than they need to be; Billy Crudup, in full CGI motion capture, makes a credible Dr. Manhattan, though at all times I was heavily distracted by the comically massive blue penis that Snyder saw fit to graft onto the character. Matthew Goode's Adrian Veidt is a bad performance, for reasons that I think have to do with his and the director's take on the character (he sounds - and looks - kind of like Faye Dunaway), while Malin Akerman as Sally Jupiter is the only flat-out horrible performer, reciting lines with a wooden intensity that recalls community theater auditions.

I suspect that Watchmen the movie is doomed to speedy obscurity. It seems like a big deal now because so many people wanted it to be a big deal, but in a year or two, when the novelty is gone and it becomes apparent that there's really nothing to the movie at all - even 300 was more of a watershed, as a technical work - it will be consigned to the footnotes of history. It is not nearly so bad as it could have been, but except for a few huge missteps (oh, God, that "Hallelujah" sex scene) it's not much of anything else: it does not illuminate the comic book, it does not particularly work as its own creature, but in neither case is it an epic failure. It's just kind of there, and if it weren't for its enormous pedigree, I think that there is where it would wither and die.